1. Field of the Invention
The present invention relates to a bound stopper, a bound stopper assembly, and a bound stopper mounting structure for a vehicle body, and more particularly to a bound stopper, a bound stopper assembly and a bound stopper mounting structure for a vehicle body, in which the bound stopper to be mounted on a vehicle body via a tubular bracket having a bottom portion with a plurality of drainage holes employs a technique for advantageously forming a drainage path for draining water that has passed through the drainage holes.
2. Description of the Related Art
In suspension systems of vehicles such as an automobile, there is conventionally disposed a bound stopper between a supporting member (e.g. an arm or a leaf spring) for supporting vehicle wheels and a vehicle body. The bound stopper prevents the supporting member from excessively moving (oscillating) in a vertical direction and from being abutted or contacted with the vehicle body (e.g. a frame), which are caused by bouncing of the vehicle wheels.
As one type of bound stoppers, there has been known a type of bound stopper, which includes a fixing metal fitting having a tubular portion and a bottom portion and a stopper body that is made of elastic material such as any of various rubbers and polyurethanes extending in an axial direction of the tubular portion of the fixing metal fitting and that is entered into the tubular portion of the fixing metal fitting at an end of the axial direction thereof to be fixed to the fixing metal fitting. In the bound stopper structured as above, when the supporting member is excessively displaced, the supporting member comes into contact with the stopper body made of elastic material, whereby the stopper body is elastically displaced. As a result, displacement of the supporting member is elastically limited.
Such bound stoppers structured as above includes bound stoppers that are each mounted on a vehicle body by fixing a fixing metal fitting to a tubular bracket having a bottom portion and being mounted on a lower surface of a vehicle body so as to be open upward in a state in which an outer surface of the bottom portion of the fixing metal fitting is in contact with an outer surface of a bottom portion of the bracket. Employment of the mounting structure described above provides an advantage in which the contact position of the stopper body of the bound stopper and the supporting member can be arbitrarily and easily changed only by changing the height of the tubular bracket, without changing the height of the bound stopper.
However, when the bound stopper is mounted on the vehicle body via the tubular bracket having the bottom portion as described above, rainwater, muddy water, or the like is likely to enter the bracket from its upwardly opening portion and to remain thereinside. This can cause corrosion, which reduces durability of the bracket, and consequently deteriorates the use durability of the bound stopper.
Under the situation mentioned above, JP-A-2006-248401 discloses a bound stopper in which a plurality of through holes are provided in a bottom portion of a fixing metal fitting which is positioned so as to contact with the bottom portion of a bracket, and a groove portion is provided on an upper surface of a stopper body to communicate with each of the through holes and on a lower surface thereof to communicate with an outside. In this case, the bracket mounted on a vehicle body has a plurality of drainage holes at the bottom portion thereof. The bound stopper is fixed to the bracket, in a state where each through hole is positioned so as to correspond to each drainage hole of the bracket, whereby the through hole and the groove portion form a drainage path communicating with the drainage hole. In this manner, rainwater, muddy water, or the like that has entered into the bracket is drained away through the drainage path by way of the drainage hole.
The conventional bound stopper having the drainage path is a so-called press-fitted type in which a part of the stopper body is fixed to the tubular portion of the fixing metal fitting by press-fitting. Accordingly, in the bound stopper, the groove portion is provided on a portion of the stopper body located inside the tubular portion of the fixing metal fitting. In this case, however, for example, after the stopper body with the groove portion and the fixing metal fitting with the through holes are separately molded, the portion of the stopper body having the groove portions is press-fitted into the tubular portion of the fixing metal fitting, whereby the bound stopper can be produced easily.
There is known another type of a bound stopper, a so-called vulcanization-bonded type, in which a part of the stopper body is entered into the tubular portion of the fixing metal fitting and the entered portion thereof is vulcanized and bonded to each of inner surfaces of the tubular portion and the bottom portion of the fixing metal fitting (see JP-A-2004-225799, for example). In the bound stopper of the vulcanization-bonded type, a force for holding the stopper body by the fixing metal fitting is made sufficiently large, so that an elastic deformation mechanism of the stopper body can be more efficiently exhibited, thereby advantageously achieving a reduction in size of the stopper body, and ultimately of the entire bound stopper. In the bound stopper of the vulcanization-bonded type, however, when forming the foregoing groove portion on the portion of the stopper body entered into the tubular portion of the fixing metal fitting, it is inevitable to make complicated the structure of a mold used for integrally vulcanizing and molding the stopper body and the fixing metal fitting, where the mold may be of a slide-type or may include a pin or the like. This causes not only a problem of a complication of the production work of the bound stopper, but also an increase of a cost burden for the production.
Additionally, in the conventional bound stopper, for either the above press-fitted type or vulcanization-bonded type, when mounted on and fixed to the bracket, the fixing metal fitting is circumferentially positioned with a visual check to confirm individual positions of the plurality of the through holes in the fixing metal fitting and the drainage holes in the bracket, upon the fixing metal fitting being in contact with the bracket, such that the plurality of the through holes correspond to those of the drainage holes, which is a very troublesome work.